Q&A with Alea German: Looking at Battery Storage for Single Family Homes
As an engineer at Frontier Energy, Alea’s focus is on whole building energy optimization, technology assessment, and code development, particularly as it relates to zero net energy (ZNE) design. Alea is a skilled energy modeler with 15 years of experience with various software tools. Overseeing Frontier’s energy code consulting services, she has a broad understanding of California’s Title 24, Part 6 code and leads statewide technical code change proposals. As a key technical lead for the California Codes and Standards Reach Codes program, Alea provides technical support to local governments on adopting ordinances to meet energy and greenhouse gas reduction goals. Over her career, she has contributed to research evaluations of residential technologies such as ventilation cooling, air to water heat pumps, and heat pump water heaters and has experience with field surveying and testing in retrofit and new construction applications. Alea, a licensed professional engineer, received her Master of Science in Mechanical Engineering from the University of California, Davis and Bachelor of Science in Mechanical Engineering from Johns Hopkins University.
Q: Tell us a little about this topic, Alea, why would stakeholders be interested in battery storage for single family homes?
A: There are numerous intertwined benefits to coupling a battery storage system with a rooftop photovoltaic (PV) system for single family homes. There are economic benefits from improving the utilization of the PV system by capturing the excess generation during the middle of the day and storing it for later. With time-of-use rates this allows for lower utility bills by reducing consumption of grid-generated power during peak periods (summer late afternoon / evening). On a larger scale, the use of these systems offers a much-needed stabilizing influence on the statewide grid by helping to level the late-day demand for power. This load shifting also results in carbon emission savings, and at the jurisdiction level policymakers can encourage adoption of battery technology to achieve their decarbonization and climate goals.
Q: What kind of resources are available for jurisdictions looking at battery storage measures?
A: The statewide reach codes team conducted a preliminary cost-effectiveness study in 2018 for the 2016 code cycle. Most recently, the team is updating this study, focusing on single family homes, for the 2019 code cycle. The updated study looks at both new construction and existing homes, using the prototypes defined by the Energy Commission. The analysis evaluates behind-the-meter battery systems coupled with a photovoltaic (PV) solar system but did not analyze stand-alone battery systems.
The report will provide valuable information for local jurisdictions interested in reach codes that target load shifting and decarbonization measures, as it includes analysis for nine different battery scenarios across all 16 climate zones.
Q: These systems can be quite expensive to install. Are there any financial resources or incentives for homeowners?
A: Yes. In fact, a key finding of the study was that battery storage systems are not yet cost-effective in the absence of these types of incentives.
On the federal side, there remains the federal residential solar energy credit, also referred to as an Investment Tax Credit, or ITC. This can be claimed on federal income taxes for a percentage of the cost of a solar photovoltaic (PV) system, as well as battery storage devices that are charged exclusively by the associated solar PV panels. In December 2020, Congress passed an extension of the ITC, which provides a 26% tax credit for systems installed in 2020-2022, and 22% for systems installed in 2023.
There may also be local incentives through the Self Generation Incentive Programs (SGIP) offered by the California investor-owned utilities.
Q: What about analysis for nonresidential buildings?
A: Further work is underway for nonresidential buildings. The newly adopted 2022 statewide Energy Standards include a prescriptive requirement for solar photovoltaic (PV) and battery storage systems for the first time for a range of building types (see the companion article in this newsletter for more information).
Q: When will the report on battery storage for single family homes be available?
A: The Reach Codes team expects to publish the report before the end of September. The webinar recording and presentation slides discussing the analysis are available here.